Prequels are deadly. They make the irresistible promise of addressing questions and digging deeper into fortified mythology, while rarely justifying the need for those answers with an individual emotional arc. When Legend of Korra Book 2 decided to divert its attention for a double feature of prequelization, there was an instant fear of “midi-chlorian” syndrome. George Lucas decided it was imperative to boil “The Force” down to a scientific explanation and he walked away with a one word way to explain the suckage of the Star Wars prequels. Did we really need an origin story for the Avatar and the world’s bending powers?

After soaking up the luscious, two-episode departure, the answer is a resounding “yes.” The legend of Wan, the first Avatar, is introduced with a bare-bones transition. Amnesiac, Korra is examined by a Fire Nation healer who determines she’s been infected by “dark energy.” The holistic treatment is a bath in an underground well of spirit water that transports Korra’s mind to the parallel dimension, where she’s greeted by the ghosts of the Avatar lineage. After brief hellos with fan favorites, a minute and a half of forceful exposition propels us into Wan’s history, a breathtaking departure from the show’s traditional animation style and a contained, compelling narrative that imbues Book 2 with a greater sense of purpose. After a handful of missteps this season, it’s a tremendous return to form.

The Legend of Korra lost a bit of its artistry this season with its switch to a new animation studio, but the Book 1 team, Studio Mir, returns to realize the stylized universe of “Beginnings.” The opening sequence is a feast for the eyes; while the characters remain detailed and articulate, the backdrops evoke the watercolor paintings and woodblock prints of East Asia. With animation big and small suffering from define homogeneity, the episodes’ pastel palette and swirling designs contemporize old school Studio Ghibli (the films of Isao Takahata come to mind) for a new generation.

The story and action live up to it. We’re introduced to Wan in a foot chase that tips its hat to Aladdin, helping us quickly identify with Wan’s plight. He’s poor, can’t feed his friends, and has too big a heart to sit by and let life take its course. He even finds his “genie,” the legendary Lion Turtle who first appeared in Avatar: The Last Airbender. The creature, who carries Wan’s city on his back, has the ability to grant any human the power to control an element — but only temporarily. Wan finds a way to bend the rules, and with the power to control fire, leads a revolt to take back the city.

There have been major gripes from the fan community this season over Korra’s inability to make the “right” decisions. Instead of being a perfect hero, she’s a human with godly powers. Unexpectedly, and what makes this story work so well, is that Wan is in the same boat. He’s a renegade, a do-gooder, and a student of life as opposed to an all-knowing “Avatar.” When it looks like he might best the Chus, his town’s regal family, Wan backs down. He can’t kill, he hasn’t thought through his plan enough to have another option, and so he’s caught with incriminating evidence of defying Lion Turtle code. Ultimately, it’s his screw ups and imperfections that realize the Avatar and bring balance to the world. Not divine intervention.

As Wan ventures out into spirit-filled woods, imagination explodes on screen. It feels like homage aplenty as a new side of the world unspools before Wan’s eyes: The Princess Bride forest, a frog looking like Rankin & Bass’s Gollum in The Hobbit, a sophisticated lemur looking like Baron from Whisper of the Heart … and that’s just the foreground. Wan’s awakening connects him with the spirit world. He arrived as a fire-wielder, erratic and dangerous. As he learns more and more from his margin doodle friends, he becomes a bender.

As he becomes immersed in the spirit world, Wan’s value grows to epic proportions. When he stumbles upon two “all-powerful spirits” wrasslin’ in a valley — par for the course in the old days — the everyman jumps into action … and fails. He breaks up the duel between Rava, the good, and Vatu, the evil, and destines mankind for ultimate destruction. Whoops. His interference speaks to the larger problem at hand: Everyone, every spirit in Wan’s world is fighting, because they’re fighting for dominance without any oversight. If things run as “they always have,” innocents will die on both sides of the lines. So Wan takes on a Lincoln-sized task. He’ll become “The Avatar,” extend his hands to both sides to both planes of existence, and stop this bleeding (spoken in a Daniel Day-Lewis voice).

Actually, that’s the voice of Steven Yeun of The Walking Dead, who does an amazing job of contending with epic speak to make Wan human in a swirling sea of the surreal. Rava explains that he has little time to enact his plan of peace, with the “Harmonic Convergence,” an alignment of the planets, acting as a countdown clock to Vatu’s mass destruction. “Part 2” becomes a masterclass in montage; Wan travels to the corners of the Earth to meet with other Lion Turtles who gift him with their individual elements — the “how’d the Avatar come to be” part of the tall tale. As he trains with Rava, he learns of his ability to unify with the spirit, and enter the Avatar State. The fluidity of these scenes is extraordinary, voice-over and picture acting as a whirlwind of expository empowerment.

Urgency builds when Wan stumbles upon his former housemates and a group of warring spirits. Creators Michael Dante DiMartino and Bryan Konietzko have professed a love for Hayao Miyazaki’s Princess Mononoke and it shows its face here. The battle is necessarily harsh (Vatu later tells Wan that all of his friends were slaughtered in the end), with no side willing to see the other. Either all spirits are bad or humans are a plague to the planet. Not even Wan’s infant Avatar State can persuade them.

Wan’s confrontation with Vatu sees the Korra creative team working on a blockbuster scale. Many of Book 1’s best scenes were small, martial arts-based fight sequences. Here, it’s a Pacific Rim-sized brawl, the closest thing we might ever see to a Shadow of the Colossus adaptation. As if the creature designs and impressionistic landscapes weren’t psychedelic enough, taking the battle to the spirit world provides even more eye candy. Wan takes the advantage when he unifies permanently with Rava and goes full Avatar mode (backed by a musical callback to Korra’s own revelatory breakthrough). They don’t make televisions big enough to do justice to this finale.

The conclusion of “Beginnings Part 1 & 2” prepares us for Book 2’s descent. Wan encases Vatu in a tree prison, declaring that he’ll shutdown the Spirit Portals that allow humans to move back and forth between worlds so that the manifestation of evil can never return to the world. And then one of the more heartbreaking moments in all of Avatar history. Jumping forward a few decades, we see Wan dying on a battlefield, asking Rava if he’s failed her. She lays him to rest, knowing that his soul will be reborn. Wan’s death will not be in vain.

Wan’s life sheds a bit of light on Unalaq’s master plan, as well as catching Korra up on what the audience anticipated. Wan provides answers, instills her with a memory, and kicks her out the door. It’s time to do what Korra does best: kick butt. But now, with an actual clue.

Odds & Ends

Korra’s visions of past Avatars was a who’s who that I never wanted to end. Aang was a given, Roku was a nice surprise, Kyoshi was a “whoa!” and when Kuruk showed up … I had to look up what his name was because whowouldathunk?

“The Chus” sounds a lot like “the Jews.”

Introducing us to Wan’s friend who is part tree was an ingenious bit of emotional world-building in this episode. Why would anyone hate these cute, cuddly spirits?! Oh right, because they can inhabit your body and permanently deform you.

If you dig through sketches from Avatar: The Last Airbender, you’ll see that the Chinese Dragon redesign of the Lion Turtle is actually closer to what Dimartino and Konietzko originally conceived. And it’s astounding.

“I’m Bushy the Bush spirit!” Wan’s moment of Sokka behavior.

What other spirit homages did you spot? The White Dragon must be a Spirited Away nod. Old Man Carrot spirit is just wonderful.

Samurai Jack fans: Does Vatu remind you of Aku?

It was very strange to hear a modern “static” sound when Wan began to phase in and out of the spirit world. That’s not a sound I had heard in the Avatar universe before.

Old McDonald wishes he owned an air bison farm. Let’s hope Korra’s new ride doesn’t replace Naga, who is severely underrepresented this season.